Hi, My name is Eric Moyers. I am a Network Support Engineer in the Cisco Small Business Support Center. I hate to be the bearer of bad news, but the AP541N does have a dual band radio, but can only broadcast on one band at a time.
What would be looking for if you wanted to be able to broadcast on both at the same time is an access-point with dual-band radios vs a dual-band radio. An example would be the Cisco Aironet 600 Series AP.
Please let me know if you have any other questions.
Eric Moyers
Cisco Network Support Engineer
CCNA, CCNA-Wireless
1-866-606-1866